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Archive for the ‘what is limestone’ Category

Waterfall in cave, originally uploaded by Mic2006.

I suppose on of the most gratifying things about cave exploration is the ‘buzz’ that you get, and everything in existence seems to be encompassed in the yellow circle of your headlamp. Outside your headlamp there is mystery – turn your head and the mystery reveals itself. Each turn, corner and passage feels like it’s own first time discovery – I guess its something like the gambler’s buzz, and once you leave the cave the buzz dies away and then I feel like i’m in this slump and the rest of the week is grey and gloomy.

First human in a place that has lain untouched for several thousand years – beat that! How can you? The greater the challenge, the more the buzz. If somebody has already gone before you and poured a concrete sidewalk where’s the wonder there? I believe caving can become an addiction, and having caved for 26 years now I am hooked just like a junkie. And oddly I’ve become a connisour of rare and unusual sights – a flowstone dam, cave pearls, speleothems and speleogens, crawling in tunnels that are washed by frigid streams, deep tannin stained pools in marble, dolostone, calcite and limestone – privy to a sleeping porcupine’s bedside, wondering if a bear lies just beyond. Where does the waterfall come from? What wondrous crystal is that? some would pay a fortune at a mineral show, I prefer the mineral exactly where it sits – a concept of eco-mineral exploration which is something quite closely allied to ethical cave exploration.

See my latest cave trip here to the incredible beauty of Marvin’s Cave and its mysterious tunnels through marble beneath a forest escarpment.

I’d have a problem topping this discovery – Mountain River Cave here.

For more on caving see my book, ‘Caving in Ontario; Exploring buried Karst’ – there is a link on the right side of the blog that will take you to Lulu where the book can be purchased.

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As I am still recovering from my mexico trip – (a nasty ailment that leaves me wishing that I’d been a little more cautious in the cenotes), we thought that we’d take it easy this weekend and though we pass Greig’s cave several times a month, we finally stopped in for a visit. Cost is $10 per adult and there is a nice picnic area, washroom, free walking sticks and the use of a flashlight, having my caving helmet I did not inquire about the cost (of the flashlight rental).

When I was younger I recall seeing that great and tacky classic ‘Quest for Fire’ and so it was with some amount of recollection that I viewed one of the larger caverns and I believe it was there that one of the epic battles between the Neanderthals and the other hairy guys took place. Another vivid memory was that unforgettable scene when the three stone-age morons were sleeping up in the tree and one of them had eaten all the leaves. I believe he was taunting a lion or a tiger beneath when the branch he was sitting on broke.

Anyway, more significantly, after a very interesting trip to Shallow Lake and the observation of one of it’s sinkholes, JC and I donned our packs and helmets and spent a little time looking for evidence of something other than the usual sea cave formative processes at Greig’s. I can’t really be totally sure of what I was seeing, I sometimes like to mull over what I have seen before I come up with a theory. For the most part there is a lot of collapse and evidence of wave action, but there was this one spot where a massive joint cut into the rock and from there a low crawling tunnel branched off along an anastomosing route – quite different from the smooth worn walls in other areas. It may have just been a rotting corroded section of rock, but the tunnels were somewhat regular and unchanging in size and one passage that I should have crawled down further, but was filled with porcupine feces, seemed to be quite promising – not so much for what you could see, but rather the floor was dirt and I wondered if there was anything that could be unearthed with a little digging (like a passage that had been miraculously overlooked). Several people have suggested the possibility of solution tunnels playing a part in the formation of Greig’s Caves – I’d like to prove that theory.

The above picture is of a little squeeze beside a pool. Up ahead JC’s camera on a telescopic extension revealed a small cavern that slopes down to the left with the possibility of further going tunnel, but that is just a guess by looking at his pictures. We both tried fitting through here, but neither of us had either the ability or inclination, but Jeff is strongly considering giving it another try – I believe he will fit. It seems that there are sseveral passages oriented along the bearing of a joint that runs somewhat parallel to the clif face – one is quite long and the crawl was increasingly painful in jeans and tanktop. I hope to prepare a little video sometime later in the week.

All in all, the $10 was well spent. The property is very scenic and we suddenly realized that we’d spent several hours in speculation. Admittedly this is not a wild cave, but it certainly has some interest and who could possibly shun it for the fact that it was the setting of that great theatrical masterpiece of my teenage years – Quest for Fire. If you are looking for a casual outing with your kids, providing you keep a good eye on them as there is plenty of opportunity for injury, this could well be one of the fun things to do near Toronto. This is a good example of what cavers call spelunking. I felt a little overdressed with my helmet, but what the heck.

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What is limestone?, originally uploaded by Mic2006.

What is limestone?

First and foremost limestone is a sedimentary rock. As seen in the picture above, it erodes and redeposits in fantastic and ornate ways.  Limestone is made of the skeletons of corals and tiny sea creatures, but it can also be made of calcium based chemical precipitates. The colors of limestone are many and varied. It is most typically a result of chemical impurities, and when subject to heat and pressure limestone meta-morphs to marble; a banded and crystalline rock that is seen in some Ontario caves as beautiful swirling bands. As is the case of the Silurian age Niagara Escarpment, when calcium is replaced in part by magnesium, dolostone forms, and although it is similar to limestone it reacts entirely differently to water.

Check out this amazing video on caves and karst landscapes. It speaks of how limestone is corroded, how sinkholes develop and what the impact of caves is upon geography – video on karst topography here.

The different types of limestone are many and varied, but two broad classification systems govern the names you will hear them by. The Folks system considers limestone upon the basis of the composition of its grains and interstitial material, while the Dunham classification is more focused upon the texture of the rock.

In relation to its cave forming potential, limestone in Ontario is situated in either the west of the province, deposited during the Devonian age and still as of yet hiding its caving potential beneath the thickly deposited glacial tills, or it it is found at the eastern edge of Ontario, at either edge of the lobe of the Canadian shield that juts southwards, down towards Kingston. Being situated at the outer edge of the former Michigan Basin, these eastern limestone’s are considered the most favorable in the province for the development of caves. The most notable cave forming limestone’s are those of the Bobcaygeon Formation a rock of the Ordovician age.

About 10% of all sedimentary rocks are classified as limestone. Other rocks that are commonly found inter-layered with limestone are sandstone, dolostone and shale. The presence of a shale layer is especially favorable to the development of caves. In our newly discovered cave – Wasteland Waterway we are expecting to come across a layer of the Rochester Shale soon. As shale is impermeable we expect it will change the nature of the system.

To read more about caves and limestone in Ontario check out my newly published book on caves,  Caving in Ontario; Exploring Buried Karst. In this book you will see mysterious tunnel systems that have developed in the limestone of the province. I also feature caves that have developed in marble and dolostone. There is a fantastic story of exploration that has remained somewhat unspoken of till now.

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